1. Field of the Invention
This invention relates to a new and improved spout fitment and a plug type cap for closing same. More particularly, the invention relates to a fitment which fits around a hole in a panel of a paperboard carton or around a hole in a flexible container such as used for packaging liquid products and powders and to a closure for such fitment. The invention is further characterized in that it is tamper evident. More particularly, the invention relates to a unitary fitment and closure molded in a single mold wherein the cap and the fitment are molded axially spaced apart. An elongated tear tab (which is one of the elements of the tamper-evident feature of the assembly) extends from the fitment up to the cap and functions during the molding process as a "runner." In other words, plastic material flows into the portion of the mold which forms the cap, thence down the tear tab runner and finally into the portion of the mold which forms the fitment. The cap may be assembled with the fitment as part of the molding process in that as the core of the mold retracts, the cap is drawn along with the core and assembles the two components together. The cap is then stripped from the core since the cap can move no further.
The invention is applicable to packaging having long shelf-life wherein a separate piece of foil or plastic material is welded to the underside of the flange of the fitment and, optionally, to the bottom edge of the cap.
2. Description of the Related Art
Generally speaking, prior fitments have spouts formed with external threads closed by caps with internal threads. Some fitments are used in conjunction with plastic bag containers, the fitment being integrally welded to the plastic bag. Other prior art fitments are attached to a polymer-coated paperboard container, such as a gable-top container which, optionally, may be lined with foil or plastic. Prior art fitments for paperboard cartons usually include a thin flange which is welded to the polymer-coated paperboard surface of the container.
It will be understood that instead of a screw thread engagement of the cap to the spout of the fitment, a snap-on, snap-off engagement may be used. Such an attachment has been previously used in the fitment art.
Fitments of the prior art have a number of deficiencies as compared to the present invention. In the first place, they employ multiple components which increase the cost of the combination very greatly over the simple structure of the present invention. Secondly, the assembly is difficult and often involves rotary equipment which is difficult to control in practice and is expensive to install. Thirdly, because of the fact that the prior art spouts are externally threaded, the diameter of the opening in the spout is restricted inasmuch as there is only limited space on the panel of the container on which the flange can be located, thereby reducing the diameter of the fitment flange and correspondingly the internal diameter of the spout. Fourthly, commercially available fitment closure combinations have no external tamper-evident features, demonstrated, for example, by the internal foil seal of the spout opening of some prior art fitments.
The openings in prior container panels have been closed by barrier layers, such as shown in U.S. Pat. No. 4,813,578. Such barrier layers are, however, usually part of the laminate of which the container panel is formed. Portions of the plug or cap are secured to the barrier so that when the plug is removed, the barrier is fractured, providing access to the interior of the container. The use of the laminate as the barrier involves manufacturing difficulties which do not occur in accordance with the present invention.
All of the foregoing deficiencies are eliminated in the present invention.